Make sure to cleanly shut the Pi down with "sudo shutdown -h now" every time. I'm yet to corrupt a Pi SD card and I have 4 of them which I've abused in a lot of different ways.
The real trouble area is the SD card reader in my experience. The pins are very easy to break off accidentally. The new B+ model uses a microSD card so it's not nearly as troublesome.
The pin issue can be somewhat mitigated with a case. If there are corridors for the SD card to slide down before entering the reader, it makes it much more difficult to contact the pins at bad angles.
This definitely worked for me anyway. Plus the case keeps the SD card from moving almost all while in position (which means you cannot suffer corruption from shaking it out of the reader, only power loss or similar).
The real trouble area is the SD card reader in my experience. The pins are very easy to break off accidentally. The new B+ model uses a microSD card so it's not nearly as troublesome.